ABSTRACT
Cow’s Milk ............................................................................................................. 129 Isolation of Milk Allergens ............................................................................... 134 Detection of Milk Allergens ............................................................................. 135
Hen’s Egg Allergy .................................................................................................. 137 Isolation of Hen’s Egg Allergens ....................................................................... 141 Detection of Hen’s Egg Allergens ..................................................................... 143
References .............................................................................................................. 145
appears to be an association of four different proteins, αs1-, αs2-, β-, and κ-casein, in approximate proportions of 40%, 10%, 40%, and 10%, respectively.3 Plasmin, the native milk protease, cleaves β-casein and generates the γ-casein fragments.4 Milk only contains trace amounts of γ-caseins, while proteolytic ripened cheeses contain plentiful amounts of γ-caseins.5 In some studies, β-lactoglobulin was found to be the fraction with the greatest sensitizing potential, while the α-lactalbumin fraction gave weaker positive reactions; casein was the least sensitizing of the fractions studied.6 This view has not been completely con‹rmed because sensitivities to the various cow’s milk proteins have been reported to be widely distributed.7,8 Nevertheless, the majority of published studies reported that caseins as well as the whey proteins were major allergens. Major allergens generally are de‹ned as proteins for which 50% or more of the allergenic patients studied have speci‹c immunoglobulin (Ig) E. Crossreactivity between cow’s milk proteins and milk proteins from other species depends on phylogenetic relationship.5 The highest homologies are observed between the milk proteins of cows and other bovidae, such as buffalo, and, less distinctive, sheep and goat. Homology of the amino acid sequence ranges from 84% for κ-casein and 96% for β-lactoglobulin.9 Soy milk and milk of mares have been reported to be alternatives for patients with cow’s milk allergy.9
